UART boot mode: fail to load u-boot to DDR

I need ideas how to debug the situation.

i have tms320dm6467 evm which fails to load u-boot by UART boot mode to DDR with serial load utility.

The UART boot mode is configured.

The options that i have is to debug RBL procedure. Need help how to start?

My loading procedure works well on another evm card. See below the whole procedure.

Running utility:

mono slh_DM646x.exe -p /dev/ttyS0 -load2DDR -startAddr 0x81000000 -loadAddr 0x81000000 u-boot.bin

Output:

Waiting for the DM646x...
BOOTME commmand received. Returning ACK and header...
ACK command sent. Waiting for BEGIN command...
        Target:   BEGIN
BEGIN commmand received. Sending CRC table...
 100% [                                                              ]
                           CRC table sent....

Waiting for DONE...
DONE received.  Sending the UBL...
 100% [                                                              ]
                              UBL sent....